The human heart is the muscle that is responsible for pumping blood throughout the vascular network. Veins are vessels that carry blood toward the heart while arteries carry blood away from the heart. The human heart consists of two atrial chambers and two ventricular chambers. Atrial chambers receive blood from the body and the ventricular chambers, which include larger muscular walls, pump blood from the heart. A septum separates the left and the right sides of the heart. Movement of the blood is as follows: blood enters the right atrium from either the superior or inferior vena cava and moves into the right ventricle. From the right ventricle, blood is pumped to the lungs via pulmonary arteries to become oxygenated. Once the blood has been oxygenated, the blood returns to the heart by entering the left atrium, via the pulmonary veins, and into the left ventricle. Finally, the blood is pumped from the left ventricle into the aorta and the vascular network.
Various devices and methods have been utilized to assist the heart in blood circulation, particularly for patients having congestive heart failure (commonly referred to as heart disease), which is a condition that results in any structural or functional cardiac disorder that impairs the ability of the heart to fill with or pump blood throughout the body. These devices generally include a pump, which can reside in a subcutaneous pump pocket, and cannulae fluidically attaching the pump to the vascular network. One cannula can be used to transmit oxygenated blood from a chamber of the heart to the pump; another cannula can be used to direct that blood from the pump to the arterial network.
It is imperative that the distal end of the cannula be stabilized with respect to the vascular structure, i.e., a tip on the distal end should not tilt away from a position that is approximately orthogonal to the wall of the vascular structure. Tilting of the distal end of the cannula can lead to localized stress on the tissue of the vascular structure and possibly a flow obstruction at the tip. While sutures used to synch the tissue surrounding the cannula are somewhat effective in creating hemostasis at the cannula insertion site and to prevent removal of the tip of the cannula, sutures alone do not prevent the movement of the tip from the orthogonal position. There continues to be a need to provide better stabilization of the cannula, particularly the tip, relative to the vascular structure by maintaining the cannula in the more orthogonal position.